Concrete pump

ABSTRACT

Concrete mix is power fed into two concrete cylinders having pistons operating in timed reciprocation with a discharge tube which swings into alignment with the cylinders so that as the concrete in one cylinder is being forced into the discharge tube, the other cylinder is being filled. The discharge tube is disposed between two power infeed screws which swing with the tube so that one of the screws is aligned with one of the cylinders while the other cylinder is being emptied.

United States Patent [72] Inventor Francis C. Wilson 8330 N. Poplar Drive, Milwaukee, Wis. 53217 [21] Appl. No. 851,348 {22] Filed Aug. 19, 1969 [45] Patented Sept. 28, 1971 [54] CONCRETE PUMP 10 Claims, 4 Drawing Figs.

[52] U.S. Cl 417/203, 417/900 [51] Int. Cl F04b 23/14 [50] Field ofSearch 417/203, 900, 199, 205, 206

[56] Relerences Cited UNITED STATES PATENTS 3,181,469 5/1965 Schumann 417/900 3,298,322 1/1967 Sherrod Primary Examiner-Robert M. Walker Attorneys-John W. Michael, Gerrit D. Foster, Bayard 1-1.

Michael, Paul R. Puerner, Joseph A. Gemignani, Andrew 0. Riteris, Daniel Van Dyke and Spencer B. Michael PATENTEnsirzsxen 3,609,065

sum 2 or 2 Jan enter jranas' K. $41902:

CONCRETE PUMP BACKGROUND OF INVENTION Prior concrete pumps in general have had problems due to use of Y-joint pipe sections which require change in direction of flow, change in the cross-sectional pumping area, and necessitate change in the velocity of the mix in transition sections. High-pressure seals are also required.

Those pumps incorporating the use of a cylinder and piston arrangement have been inadequate in properly and completely filling the cylinder thereby causing shock, volumetric inefficiency and excessive idle travel of the piston. Prior proposals have also failed to provide convenient access to all parts or areas requiring cleaning or service during operation or in cleanup.

SUMMARY OF INVENTION The concrete mix is fed into a feed hopper which includes a filter means and agitating means, the latter moving the mix into a drop hopper. The drop hopper is stationary except for a front swing wall which includes a discharge tube extending through it, said tube being disposed between two power infeed screws which are mounted for rotation on their own axes normal to the swing wall and swing with the swing wall, said screws and tube swinging (driven) jointly in an arc with said swing wall. Two adjacent cylinders are provided for alternate communication with the infeed screws and discharge tube so one cylinder is filled by one of the infeed screws while the other is discharging the mix through the discharge tube. Each cylinder includes a reciprocally mounted piston operating in timed relationship to the swinging of the swing wall assembly to alternately fill and empty the cylinders thereby maintaining a substantially constant flow of concrete through the discharge tube into the distribution hose.

The present invention provides a large capacity pump with maximum mix tolerance and adaptability and which can be readily transported and serviced in a short time by practical manual methods. In addition, the objects of this invention gave priority attention to continuous smooth flow of various concrete mixes including maximum tolerance for high rock content and poorly graded or partially mixed concrete.

DESCRIPTION OF DRAWINGS FIG. 1 is a plan view of the concrete pump proposed by this invention.

FIG. 2 is a side elevational view taken in section generally along line 2-2 of FIG. 1.

FIG. 3 is an end view of the discharge end of the proposed concrete pump.

FIG. 4 is a cross-sectional view of the proposed concrete pump taken generally along line 44 of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIIVIENT This invention will probably find particular application for transferring large volumes of freshly mixed concrete via pipe lines and hoses. In view of this, the particular embodiment to be described is referred to as a concrete pump, but it will be appreciated that the device may be used for pumping any of various types of fluids and semifluid materials.

Referring now to the drawings in detail, the concrete pump is shown in combination with a conventional tandem trailer 12 having a suitable frame 14 to support the pump structure.

Freshly mixed concrete is deposited into feed hopper 16, the hopper having sloped sides 18 and a curved bottom 20 (shown in FIG. 4) in which power feed screw 22 is provided to force the mix into drop hopper 24. As shown in FIG. 4, the feed screw has a radius essentially equal to that of curved bottom 20 so that there is minimal opportunity for deposits to remain in the feed hopper. Feed screw 22 may be reversed in case of jamming. Ideally, the screw is automatically reversed for a small part of a revolution and then driven forward in the event the force required to turn the screw rises above an adjustable predetermined level. Feed hopper screw 22 can be swung out of the hopper on loose pin hinge mounts 23 and/or removed entirely along with the feed hopper screw drive motor 28. A removable bulkhead can be fitted between the drop hopper and the feed hopper to mix or to retain material in the feed hopper only, such as at startup or during delays, to continue agitation of the mix.

In order to minimize the entry of oversized particles into feed hopper 16, a screen 26 is provided across the top of hopper 16, the screen being attached to the hopper by a hinge 29 which permits swinging of screen 26 out of position to clean oversized particles which have collected on the screen. To achieve a more efficient screening operation, vibrator 30 may be provided to vibrate screen 26 throughout the loading process.

Drop hopper 24 is essentially semicircular in cross section, as shown in FIG. 4, such that the mix feeding into it from feed hopper 16 will likewise gravitate towards the bottom 32. However, wall 34 of hopper 24 is swingably mounted about the axis of shaft 36. 1

Attached to the bottom portion of swing wall 34 for movement with it are a pair of power infeed screws 38 and 40 with a tube 42 intermediate screws 38 and 40, the axis of the screws and tube lying on the same arc from shaft 36. Tube 42 extends through swing wall 34 to the stationary face 44 of the drop hopper 24.

A pair of concrete cylinders 46 and 48 are provided for discharging the mix through tube 42. Each cylinder includes a ram piston 50 which moves back and forth through a fill and unload cycle. The cylinders are positioned forward of drop hopper 24 and beneath feed hopper 16 and are aligned so that as wall 34 swings, tube 42 comes into axial alignment with one or the other of the cylinders.

The power infeed screws 38 and 40 are mounted on wall 34 to swing with the wall and are positioned adjacent tube 42 so when tube 42 is aligned with either cylinder 46 or 48, one of screws 38 and 40 will be aligned with the other cylinder to assist in the charging thereof. The screws rotate about their axes and are preferably driven by adjustable speed hydraulic motors (not shown) which may be reversed or stopped.

During the fill cycle, a suction is created in the cylinder as the piston moves away from drop hopper 24, thus tending to draw mix into the cylinder while one of the power infeed screws assists in forcing mix into the cylinder. The use of power to assist the charging of the concrete cylinders provides complete and rapid filling of the pump cylinders.

The pistons operate in reciprocal sequence so one cylinder is being filled with mix while the other is discharging mix. Tube 42 is provided with a discharge tube 52 lining tube 42 and secured by driven wedges 54,54 shown clearly in FIG. 2. Discharge tube 52 is turned in threaded nut 56 to adjust the clearance between the entry end 58 of discharge tube 52 and stationary wear plate 60 on the drop hopper wall 44 at the concrete cylinder end.

The discharge end 62 of tube 52 is adapted to receive a rubber hose (not shown) connecting the delivery pipe (not shown) to the tube. By removing wedges 54,54, discharge tube 52 may be manually removed without disconnecting the rubber hose connection to the delivery pipe. This facilitates cleaning out material and tube 52 can be readily replaced by driving wedges 54,54 back in place. The wedged slot area is so constructed that the same wedges may be installed in reverse to assist in starting the removal of the discharge tube.

The outer tube 42 is secured to swing wall 34 by a fitted pin 63 and wedge 64. Swing wall 34 rotates about axle 36 supported by thrust bearings 66,66 and is moved by swing shockabsorbing cylinders 68,68 in timed relation to the pistons in main concrete cylinders 46,48.

A low-pressure seal 69 is provided at the junction of swing wall 34 and stationary walls and bottom 70 of drop hopper 24. The seal 69 is a rectangular elastomeric strip that can be reversed as wear progresses. The wear surface 72 on the fixed walls and bottom is a hardened material and can be unbolted for replacement.

The mechanism driving the reciprocal concrete pistons (mechanical or hydraulic), chassis, and other structural details of the machine are of ordinary construction and need not be specifically described for the purpose of this invention.

The above embodiment provides a rugged, reliable pump within a small envelope with a low loading height. As used in combination with a trailer, the pump is very portable and provides a construction that allows ready adaptation to various prime power sources such as diesel, electric, P.T.O., pnuematic motor and turbine. In addition, the pump could easily be mounted on various types of carriers and incorporated into other types of machines, for example, transporters, tunnel cars and the like.

I claim:

1. A pump comprising:

a hopper;

a pair of pump cylinders, each cylinder alternately being filled with mix from the hopper and discharging the mix into a discharge system;

a piston reciprocally mounted in each cylinder, the pistons operating in timed reciprocal relation so one cylinder is filled with mix while the other cylinder is discharging the mix;

and power means located in the hopper in general alignment with the cylinder being charged and operative to force mix into the cylinders during their respective fill cycles.

2. The combination according to claim 1 wherein said power means includes a pair of power infeed screws, said screws rotating about their own axes and alternately communicating with the cylinder being charged with mix.

3. The combination in a concrete pump comprising:

a hopper for receiving mix and including a wall mounted for rotation about an axis;

a pair of pump cylinders in fluid communication with said hopper for receipt of said mix from said hopper;

a discharge tube mounted on said wall for rotation with it, said tube having an inlet and outlet with a passageway therebetween, said inlet alternately communicating with each of said cylinders as said wall is rotated, said outlet communicating with a discharge pipe system;

a piston reciprocally mounted in each cylinder, said pistons operating in timed reciprocal relation to the movement of said wall and discharge tube so one cylinder is filled with mix from said hopper while the other cylinder is discharging the mix into the discharge tube;

a pair of power infeed screws mounted on said wall for rotation about their own axes, said screws alternately communicating with the cylinder being charged with mix.

4. The combination according to claim 3 wherein said discharge tube is disposed intermediate said infeed screws,

said discharge tube and screws being on a common are from the rotation axis of said wall whereby when one of said cylinders is aligned with the tube for discharge of mix, the other cylinder is aligned with one of said screws for the filling of said other cylinder.

5. The combination according to claim 4 wherein said hopper is comprised of a first and second portion, said first portion positioned to deliver mix to the second portion and including a feed screw for agitating and moving the mix from said first portion into said second portion.

6. Pumping apparatus comprising:

a pump cylinder;

a feed hopper communicating with the cylinder;

a piston in the cylinder;

means reciprocating the piston so the cylinder is alternately charged from the hopper and then discharged;

said hopper including a wall portion mounted for rotational movement about an axis;

a straight discharge tube parallel to said axis and extending through said wall portion for movement therewith about said axis;

the end of the tube inside the hopper serving as an inlet and being registerable with the cylinder to receive the discharge from the cylinder; means moving said wall portion in timed relation to the piston actuation to register the tube inlet with the cylinder during discharge and move it out of register for charging.

7. Apparatus according to claim 6 including power means mounted in the hopper for forcing concrete into the cylinder during the charging stroke of the piston.

8. Apparatus according to claim '7 in which the power means includes a feed screw registerable with the cylinder during the charging stroke of the piston.

9. Apparatus according to claim 8 in which a plurality of cylinders and associated pistons are employed, said power means being registerable with the respective cylinders during the charging stroke of their respective pistons.

10. A pump comprising:

a cylinder;

a piston in the cylinder;

a hopper adjacent the cylinder; I

means reciprocating the piston to alternately charge the cylinder from the hopper and discharge the cylinder contents;

a discharge conduit in the hopper;

means moving the conduit into registry with the cylinder to receive the material discharged therefrom;

and a power feed device in the hopper movable into registry with the cylinder to force material from the hopper into the cylinder during the charging stroke of the piston. 

1. A pump comprising: a hopper; a pair of pump cylinders, each cylinder alternately being filled with mix from the hopper and discharging the mix into a discharge system; a piston reciprocally mounted in each cylinder, the pistons operating in timed reciprocal relation so one cylinder is filled with mix while the other cylinder is discharging the mix; and power means located in the hopper in general alignment with the cylinder being charged and operative to force mix into the cylinders during their respective fill cycles.
 2. The combination according to claim 1 wherein said power means includes a pair of power infeed screws, said screws rotating about their own axes and alternately communicating with the cylinder being charged with mix.
 3. The combination in a concrete pump comprising: a hopper for receiving mix and including a wall mounted for rotation about an axis; a pair of pump cylinders in fluid communication with said hopper for receipt of said mix from said hopper; a discharge tube mounted on said wall for rotation with it, said tube having an inlet and outlet with a passageway therebetween, said inlet alternately communicating with each of said cylinders as said wall is rotated, said outlet communicating with a discharge pipe system; a piston reciprocally mounted in each cylinder, said pistons operating in timed reciprocal relation to the movement of said wall and discharge tube so one cylinder is filled with mix from said hopper while the other cylinder is discharging the mix into the discharge tube; a pair of power infeed screws mounted on said wall for rotation about their own axes, said screws alternately communicating with the cylinder being charged with mix.
 4. The combination according to claim 3 wherein said discharge tube is disposed intermediate said infeed screws, said discharge tube and screws being on a common arc from the rotation axis of said wall whereby when one of said cylinders is aligned with the tube for discharge of mix, the other cylinder is aligned with one of said screws for the filling of said other cylinder.
 5. The combination according to claim 4 wherein said hopper is comprised of a first and second portion, said first portion positioned to deliver mix to the second portion and including a feed screw for agitaTing and moving the mix from said first portion into said second portion.
 6. Pumping apparatus comprising: a pump cylinder; a feed hopper communicating with the cylinder; a piston in the cylinder; means reciprocating the piston so the cylinder is alternately charged from the hopper and then discharged; said hopper including a wall portion mounted for rotational movement about an axis; a straight discharge tube parallel to said axis and extending through said wall portion for movement therewith about said axis; the end of the tube inside the hopper serving as an inlet and being registerable with the cylinder to receive the discharge from the cylinder; means moving said wall portion in timed relation to the piston actuation to register the tube inlet with the cylinder during discharge and move it out of register for charging.
 7. Apparatus according to claim 6 including power means mounted in the hopper for forcing concrete into the cylinder during the charging stroke of the piston.
 8. Apparatus according to claim 7 in which the power means includes a feed screw registerable with the cylinder during the charging stroke of the piston.
 9. Apparatus according to claim 8 in which a plurality of cylinders and associated pistons are employed, said power means being registerable with the respective cylinders during the charging stroke of their respective pistons.
 10. A pump comprising: a cylinder; a piston in the cylinder; a hopper adjacent the cylinder; means reciprocating the piston to alternately charge the cylinder from the hopper and discharge the cylinder contents; a discharge conduit in the hopper; means moving the conduit into registry with the cylinder to receive the material discharged therefrom; and a power feed device in the hopper movable into registry with the cylinder to force material from the hopper into the cylinder during the charging stroke of the piston. 